Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 12-09-2008, 16:25   #1
Registered User
 
bobalpep's Avatar

Join Date: Jun 2008
Location: Kent Narrows, Md.
Boat: Gemini,3200, 32', My-Gem-An-I
Posts: 18
delta blues

I've had about a snoot full of my 22# delta plow particularly resetting.
Boat's a 7500# Gemini cat, I've tried; increasing (3/8" )chain to 10', tried to be extra careful on the initial set(but aux. is only 10 HP), different scopes but still have poor reliability if it has to reset to a different wind direction. We usually anchor in shallow water, about 4 or 5' with muddy bottoms (Chesapeake Bay)
Anybody got any ideas besides getting rid of the delta? Maybe more chain or does it do any good to sharpen the point of the plow?
thanks
Bob
__________________

__________________
bobalpep is offline   Reply With Quote
Old 12-09-2008, 17:28   #2
Eternal Member
 
Ancora Latina's Avatar

Community Sponsor
Cruisers Forum Supporter

Join Date: Dec 2007
Location: Florianopolis - Brasil
Posts: 121
Quote:
Originally Posted by bobalpep View Post
Anybody got any ideas besides getting rid of the delta? thanks
Bob
Ask any mechanic which is the cutting angle of any tool??

According to the hardness the material and to the cutting speed, the cutting angles are perfectly defined.

To generalize, the cutting angle is roughly that of a “wood chisel”.

An anchor is also a “cutting tool” which must penetrate a material: sea-beds.

By chance these sea-beds are usually rather tender, and even a tool with a bad cutting angle will be able to penetrate. But as soon as the material changes: hard sand, algae... the anchor which has a bad cutting angle will not penetrate.

The solution?:
- To modify the cutting angle so that it is of the “Wood chisel” type.

Second important parameter: the pressure exerted on the cutting tool, more this pressure will be high, more the tool (anchor) will easily penetrate.
With regard to anchors, this pressure is of two types:

- a) initial pressure or static pressure: it is the pressure exerted by the point(s) of the anchor on the funds; it varies in an important way, approximately from 18% up to 50% of the total weight of the anchor and, of course, more the point will be heavy, more the anchor will tend to penetrate
- b) dynamic pressure: when the anchor begins its static penetration, the traction of the mooring line will continue to dig the anchor in.

In your precise case:

- To change the angle of attack: impossible,

- To increase the weight on the point, not easy but feasible!

But “the” solution is to select an anchor having an angle of attack in “Wood chisel” and anchors having the best distribution of weight at the level of the point (and the best ratio: Holding surface area /weight)
__________________
Ancora Latina
www.ancoralatina.com
Ancora Latina is offline   Reply With Quote
Old 12-09-2008, 17:37   #3
Marine Service Provider
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,618
Bob, First the Chesapeake is all pretty soft mud in most places and that is the reason you will see lots of Danforth type anchors on the boats around you. 10 feet of chain, IMHO, is not enough and even in 4 to 5 feet you will need at minimum a 7 to 1 scope based on water depth and the height of the bow above the water. I also think the 22 is a bit light for your boat. It may not weigh much but it has a lot of windage. Resetting in wind and current changes are always an issue and much improved with additional chain and heavier anchors.
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 12-09-2008, 17:43   #4
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Bob,

My prescription:

1. Ditch the Delta, or relegate it to a backup;

2. Get a FX23 Fortress; and

3. Don't look back.

:-)

Bill
__________________
btrayfors is offline   Reply With Quote
Old 12-09-2008, 18:29   #5
Registered User
 
bobalpep's Avatar

Join Date: Jun 2008
Location: Kent Narrows, Md.
Boat: Gemini,3200, 32', My-Gem-An-I
Posts: 18
delta blues

Chuck;
What I meant to state was 10' of chain with whatever nylon necessary to achieve a adequate scope.Originally it had 5' of chain, I do not notice any improvement with the extra 5' of chain.
Bob
__________________
bobalpep is offline   Reply With Quote
Old 12-09-2008, 18:42   #6
Marine Service Provider
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,618
Bob, I understood what you meant but 10 feet is still not enough and 5 feet is worthless. But you still need to reconsider replacing the anchor. Let's see, save a few bucks, sleep at night?
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 13-09-2008, 00:17   #7
Senior Cruiser
 
Alan Wheeler's Avatar

Cruisers Forum Supporter

Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
Images: 102
A rule of thumb is 1.5 x the boat length in chain. If you don't have that much, the anchor can never be trusted. Then 5:1 minimum, preferably 7:1 scope of rope rode.
__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 13-09-2008, 07:02   #8
CF Adviser
Moderator Emeritus
 
Hud3's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,929
Images: 49
I don't think that the fact that you anchor is a Delta is the problem. 22 lbs is too small, and as others have advised, not nearly enough chain. I had very good results anchoring with my 44 lb Delta & all-chain rode in the Chesapeake. I watched it re-set within about 5 feet when the wind shifted 180 degrees (a sea breeze came up).

The Danforth/Fortress style anchors are good, too, but may have trouble setting in grass.
__________________
Hud
Hud3 is offline   Reply With Quote
Old 13-09-2008, 09:08   #9
Senior Cruiser
 
Vasco's Avatar

Cruisers Forum Supporter

Join Date: Apr 2004
Location: Toronto
Boat: CS36Merlin, "La Belle Aurore" Ben393 "Breathless"
Posts: 7,138
Ditto. It's not the Delta. They're pretty good, more chain, maybe a bigger anchor. Most anything'll hold in that Chesapeake mud.
__________________
Rick I
Toronto in summer, Bahamas in winter.
http://groups.yahoo.com/group/beneteau393/
Vasco is offline   Reply With Quote
Old 13-09-2008, 15:49   #10
Eternal Member
 
Ancora Latina's Avatar

Community Sponsor
Cruisers Forum Supporter

Join Date: Dec 2007
Location: Florianopolis - Brasil
Posts: 121
[quote=Vasco;204953] Ditto. It's not the Delta. They're pretty good, more chain, maybe a bigger anchor. Most anything'll hold in that Chesapeake mud. [/quote]

If it is not the anchor nor the mooring line?? can it be “Gremlins” in Chesapeake bay??

A heavier anchor (bigger) will tend to better penetrate (static penetration) but a 22 lbs anchor should set, regardless the size of the boat:

Later on, if the anchor is too small, its maximum holding will be reduced, but the size of the anchor does not explain the problem of penetration.

The chain?? some claim that it is not the anchor which holds the boat. but the chain??
A thing is indisputable, more horizontal the traction, better the behavior of the anchor, but as long as the anchor is not set, regardless the length of chain, it is posed horizontal on the seaflors, one needs a relatively important traction to raise it, which means that the anchor is set !.

For me, if the scope is sufficient, the problem of penetration can only be a question of design of the anchor

Below you will find an extract of a test done by a recognized expert in anchors, even a small anchor can “slowed the boat so violently that most testers were knocked off to their feet”.

This is Chuck Hawley from West Marine. I've been testing anchors for over a decade in the same location off of Santa Cruz Harbor. The smallest *** anchor is able to withstand almost full power from a 170HP Yanmar and a 16" propeller on Showtime, our Fortier 26 test boat. Our veering test was to set it at 1,000 lb, then slack the line and to run the boat at 6 knots perpendicular to the previous direction of pull. The anchor did not release, and slowed Showtime so violently that most testers were knocked off their feet.

Then, anchors or chains? the bets are open
__________________
Ancora Latina
www.ancoralatina.com
Ancora Latina is offline   Reply With Quote
Old 13-09-2008, 16:16   #11
Moderator Emeritus
 
Pblais's Avatar

Join Date: Mar 2003
Location: Hayes, VA
Boat: Gozzard 36
Posts: 8,700
Images: 15
Send a message via Skype™ to Pblais
Quote:
A rule of thumb is 1.5 x the boat length in chain.
Alan is correct. try it and see if it isn't more than enough. More chain would maybe do it but I also agree a 22 is too little 33 would be more like it. The Chesapeake isn't hard to anchor in and you need a heavier system to hold in weather. Without getting into which anchor type is better you would be wise to add some more chain if you had to do only one thing.

If just more chain won't work then you need to use the same chain for a bigger anchor. On the Bay I always set first time and have dragged one time and failed to set on the first shot once as well. I'm more in favor of all chain. Rope is for dock lines.
__________________
Paul Blais
s/v Bright Eyes Gozzard 36
37 15.7 N 76 28.9 W
Pblais is offline   Reply With Quote
Old 20-09-2008, 01:00   #12
Marine Service Provider
 
GMac's Avatar

Join Date: Oct 2005
Location: North of the Bridge, thankfully
Boat: R930
Posts: 1,659
10ft of chain is just silly and almost pointless. I'm not surprised you're not having a good experience.

If you don't have a winch go for 15mts (45ft) of 5/16". Don't waste the money on G40 just get BBB. Weight difference is plus 35lbs, performance difference will be huge.

If you have a winch at least double the 3/8" in length, preferably triple it.

The anchor is on the small side for 32ft Cat. And for soft sloppy bottoms you want a danforth and/or fortress pattern preferably. Bigger attack angles. That new Raya has a mud setting as well so should be worth a good look.
__________________
GMac is offline   Reply With Quote
Old 21-09-2008, 10:58   #13
Registered User

Join Date: May 2008
Location: South Africa
Boat: 58 ft catamaran
Posts: 8
Images: 2
Is the anchor an original Delta made from manganese steel or is it one of the new mild steel Chinese copies made under license to Lewmar and sold under the Delta name?

I have just bought a 63kg "Delta" from my local Lewmar agent under the misleading impression that I was getting an original " Delta Fast-Set" as depicted in their brochure - instead I have received a horrible looking galvinised mild steel Chinese copy (made no doubt from all the scrap metal they are buying up from around the globe).

To get to the points that might interest you - the tip is blunt, the leading edges are rounded, the anchor does NOT self-right as stated in their brochure and the specifications have been downgraded (tensile strengths).

The other anchor copies sold by Lewmar are the Claw(Bruce) and CQR. If the dismal test results of these two are anything to go by I may have just spent 1300 dollars on a large doorstop.

Anybody interested in it?
__________________
yellowsands is offline   Reply With Quote
Old 21-09-2008, 13:32   #14
Marine Service Provider
 
GMac's Avatar

Join Date: Oct 2005
Location: North of the Bridge, thankfully
Boat: R930
Posts: 1,659
There are genuine Deltas made in china and now they are off patent there are copies made in china.
I've actually seen a couple of copies we think are actually better than the original. A couple of small shape tweaks, intentional or not I don't know.
__________________
GMac is offline   Reply With Quote
Old 28-09-2008, 17:45   #15
Registered User

Join Date: Mar 2008
Boat: Little Harbor Whisperjet 40
Posts: 334
Anchor system

The most up to date book on the subject (2008) is by Alain Poiraud, titled The Complete Anchoring Handbook.
There is a section on cats. They need a bigger anchor ,next size up and a bridle long enough to form a 30 degree V.
A very interesting section in the appendix examines the holding power in deep verses shallow water. You need a higher scope in shallow water!
say 7:1 verses 5:1. to have the same holding.
Remember to add the height of the bow above the water line to the depth and the increase of depth due to tide.
5' of water plus 5' to the bow at 7:1 is 70 feet. Plus 7 feet for every foot in tide beyond that. Mark the line and do the math!

Oh yea, you need more chain and a bigger anchor (maybe)

Be safe
__________________

__________________
Highlander40 is offline   Reply With Quote
Reply

Tags
anchor, delta

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
I've got the Varnish Blues chris_sv Construction, Maintenance & Refit 9 15-06-2008 22:33
Delta vs CQR, sizing, etc. Schweinsberg Anchoring & Mooring 77 07-12-2007 16:12
Boat yard blues starfish62 Construction, Maintenance & Refit 8 23-10-2007 14:21
Yard Bill Blues Chief Engineer The Sailor's Confessional 2 28-06-2007 23:11
Perkins starter blues Alan Wheeler Engines and Propulsion Systems 8 13-04-2007 02:54



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:51.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.